I. Technical Field
The present invention relates to component mounting methods for mounting components on a substrate.
II. Description of the Related Art
A mounted-substrate manufacturing system, which manufactures substrates on each of which components are mounted (hereinafter, referred to as “component mounted substrates” or “mounted substrates”), includes; a printer that prints solder paste on each substrate; mounters that mounts components on the substrate with printed solder paste; and a reflow machine that solders the mounted components.
Substrates to be mounted with components are transported on a line of a conveyer in the mounted-substrate manufacturing system and manufactured as mounted substrates in the conveyer system. More specifically, respective machines perform their processes for each substrate. For example, for each substrate, the printer prints solder paste on the substrate, the mounter mounts various-sized numerous components on the substrate, and then the reflow machine solders the components. Each of the mounted substrates is manufactured in a series of manufacturing processes performed by these machines. Such a mounted substrate manufactured in the above-described manner is eventually embedded in an end product such as a home appliance.
This mounted-substrate manufacturing system sometimes produces defective component mounted substrates. From among various causes of poor quality, there is a defect in printing solder paste. For example, if a defect occurs in printing solder paste on a substrate but subsequent processes are performed on the printed substrate, in more details, components are mounted and soldered on the substrate, this results in various wastes in use of the mounted-substrate manufacturing system, consumption of the components, and the like.
To reduce the number of defective products and reduce waste processes in the mounted-substrate manufacturing system, it is effective to detect the occurrence of a defect in an early stage and take measures when the defect occurs in the middle of a series of the manufacturing processes.
Conventionally, there is a technology by which an inspection machine arranged for a process subsequent to a printing process inspects how a printer prints solder paste on each substrate. In another technology, an inspection machine arranged for a process subsequent to a mounting process inspects how a component mounter mounts components on each substrate. In a still another technology, a camera provided to a component mounter captures an image from above, then before mounting components, based on the image it is inspected how solder paste is printed on each substrate, and mounting positions of the components are corrected based on positional deviation of the detected solder paste. An example of these technologies is disclosed in Japanese Patent No. 3656533. If the above-mentioned technology detects that the positional deviation of solder paste is too large to be adjusted simply by correcting the mounting positions, it is one of measures that processing for the substrate is terminated to stop subsequent processes. For example, the substrate is removed from the path.